Sleep apnoea sufferers often snore loudly and have broken sleep, but more seriously are likely to stop breathing entirely for short periods because their airways are obstructed.

Now, new research from the US points to memory problems early on for people who have difficulty breathing while asleep.

The findings have been published in the journal Neurology, as Mandie Sami reports.

(Sound of loud snoring)

MANDIE SAMI: This is what sleep apnoea sounds like. The muscles around the throat relax, blocking the airways, making it hard to breathe.

MAREE BARNES: It's not just snoring, it's not just a noisy problem that happens in your bed partner and you kick 'em and they turn over and they stop. Snoring really is a sign that there might be something else going wrong. So I'm really hoping that people will look at this and think gosh, you know sleep apnoea is more than just a nuisance that I snore, sleep apnoea can actually lead to significant consequences.

MANDIE SAMI: That's Doctor Maree Barnes, a sleep physician and the incoming president of the Australasian Sleep Association.

The type of consequences she's talking about are the ones discovered by US scientists who checked the medical records of 2,400 people aged over 55.

They found that those who said they suffered from sleep apnoea reported problems with their memory and thinking skills a decade earlier than people who slept well.

The study's leader is Doctor Ricardo Osorio.

RICARDO OSORIO: These sleep apnoea patients declined at age 73 while those that did not have sleep apnoea declined 10 years later. So in a way one of the findings of the study was that having sleep apnoea advanced (inaudible) decline in the (inaudible).

RICARDO OSORIO: Ah, it surprised me. I was expecting that it was going to be different but I was not expecting there was such a big gap. So in that sense, yeah, we were surprised.

MANDIE SAMI: The small number of patients who did receive treatment for their sleep apnoea didn't report memory problems early on. So Dr Osorio says treatment is key.

RICARDO OSORIO: If you treat sleep apnoea you may be able to reverse early decline.

MANDIE SAMI: The ASA's Dr Maree Barnes says the research adds to growing evidence that poor sleep is associated with illness.

MAREE BARNES: So we know that not sleeping properly and having the fluctuation in oxygen levels that you have if you have sleep apnoea is not good for the brain, and it's not good for the brain not only while you're sleeping but it also has long term effects.

We know that sleep apnoea is associated with obesity and the prevalence of obesity in our society is growing and particularly this is so in our younger people, right down to children in fact.

So we expect that the prevalence of obstructive sleep apnoea is also going to increase. Along with that will go all those diseases that are associated with obstructive sleep apnoea, including perhaps dementia, mild cognitive impairment, stroke, certainly high-blood pressure, heart attacks, diabetes.

And it's really important to not ignore the signs and the things that you notice but to go along and have somebody look at it and have it treated.

MANDIE SAMI: What are some of the signs for people who hear this, you know, that they could look out for?

MAREE BARNES: The main symptom of sleep apnoea that people generally complain of is the snoring. The other things that people complain of are being tired during the day and waking up in the morning feeling unrefreshed.

But if I go along as soon as I notice that I have problems and have it treated then I can avoid that. So I'm really hoping that people will think seriously about whether they may have sleep apnoea, go and seek medical assistance for this, have it treated and hopefully avoid some of these consequences.